Moving System Databases

This topic describes how to move system databases in SQL Server. Moving system databases may be useful in the following situations:

• Failure recovery. For example, the database is in suspect mode or has shut down because of a hardware failure.

• Planned relocation.

• Relocation for scheduled disk maintenance.

The following procedures apply to moving database files within the same instance of SQL Server. To move a database to another instance of SQL Server or to another server, use the backup and restore or detach and attach operations.

The procedures in this topic require the logical name of the database files. To obtain the name, query the name column in the sys.master_files catalog view.

Important

If you move a system database and later rebuild the master database, you must move the system database again because the rebuild operation installs all system databases to their default location. For more information about rebuilding the master database, see "Rebuilding System Databases, Rebuilding the Registry" in How to: Install SQL Server 2008 from the Command Prompt.

Planned Relocation and Scheduled Disk Maintenance Procedure

To move a system database data or log file as part of a planned relocation or scheduled maintenance operation, follow these steps. This procedure applies to all system databases except the master and Resource databases.

1. For each file to be moved, run the following statement.

   ALTER DATABASE database_name MODIFY FILE ( NAME = logical_name , FILENAME = 'new_path\os_file_name' )
   

2. Stop the instance of SQL Server or shut down the system to perform maintenance. For more information, see Stopping Services.

3. Move the file or files to the new location.

4. Restart the instance of SQL Server or the server. For more information, see Starting and Restarting Services.

5. Verify the file change by running the following query.

   SELECT name, physical_name AS CurrentLocation, state_desc
   FROM sys.master_files
   WHERE database_id = DB_ID(N'<database_name>');
   

If the msdb database is moved and the instance of SQL Server is configured for Database Mail, complete these additional steps.

1. Verify that Service Broker is enabled for the msdb database by running the following query.

   SELECT is_broker_enabled 
   FROM sys.databases
   WHERE name = N'msdb';
   

   For more information about enabling Service Broker, see ALTER DATABASE (Transact-SQL).

2. Verify that Database Mail is working by sending a test mail. For more information, see Troubleshooting Database Mail.

Failure Recovery Procedure

If a file must be moved because of a hardware failure, follow these steps to relocate the file to a new location. This procedure applies to all system databases except the master and Resource databases.

Important

If the database cannot be started, that is it is in suspect mode or in an unrecovered state, only members of the sysadmin fixed role can move the file.

1. Stop the instance of SQL Server if it is started.

2. Start the instance of SQL Server in master-only recovery mode by entering one of the following commands at the command prompt. The parameters specified in these commands are case sensitive. The commands fail when the parameters are not specified as shown.

   • For the default (MSSQLSERVER) instance, run the following command:

     NET START MSSQLSERVER /f /T3608
     

   • For a named instance, run the following command:

     NET START MSSQL$instancename /f /T3608
     

   For more information, see How to: Start an Instance of SQL Server (net Commands).

3. For each file to be moved, use sqlcmd commands or SQL Server Management Studio to run the following statement.

   ALTER DATABASE database_name MODIFY FILE( NAME = logical_name , FILENAME = 'new_path\os_file_name' )
   

   For more information about using the sqlcmd utility, see Using the sqlcmd Utility.

4. Exit the sqlcmd utility or SQL Server Management Studio.

5. Stop the instance of SQL Server. For example, run NET STOP MSSQLSERVER.

6. Move the file or files to the new location.

7. Restart the instance of SQL Server. For example, run NET START MSSQLSERVER.

8. Verify the file change by running the following query.

   SELECT name, physical_name AS CurrentLocation, state_desc
   FROM sys.master_files
   WHERE database_id = DB_ID(N'<database_name>');
   

Moving the master Database

To move the master database, follow these steps.

1. From the Start menu, point to All Programs, point to Microsoft SQL Server, point to Configuration Tools, and then click SQL Server Configuration Manager.

2. In the SQL Server Services node, right-click the instance of SQL Server (for example, SQL Server (MSSQLSERVER)) and choose Properties.

3. In the SQL Server (instance_name) Properties dialog box, click the Advanced tab.

4. Edit the Startup Parameters values to point to the planned location for the master database data and log files, and click OK. Moving the error log file is optional.

   The parameter value for the data file must follow the -d parameter and the value for the log file must follow the -l parameter. The following example shows the parameter values for the default location of the master data and log files.

   -dC:\Program Files\Microsoft SQL Server\MSSQL10.MSSQLSERVER\MSSQL\DATA\
   master.mdf;-eC:\Program Files\Microsoft SQL Server\MSSQL10.MSSQLSERVER\MSSQL\
   LOG\ERRORLOG;-lC:\Program Files\Microsoft SQL Server\MSSQL10.MSSQLSERVER\MSSQL\
   DATA\mastlog.ldf
   

   If the planned relocation for the master data and log files is E:\SQLData, the parameter values would be changed as follows:

   -dE:\SQLData\master.mdf;-eC:\Program Files\Microsoft SQL Server\MSSQL10.MSSQLSERVER\MSSQL\LOG\ERRORLOG;-lE:\SQLData\mastlog.ldf
   

5. Stop the instance of SQL Server by right-clicking the instance name and choosing Stop.

6. Move the master.mdf and mastlog.ldf files to the new location.

7. Restart the instance of SQL Server.

8. Verify the file change for the master database by running the following query.

   SELECT name, physical_name AS CurrentLocation, state_desc
   FROM sys.master_files
   WHERE database_id = DB_ID('master');
   GO
   

Moving the Resource Database

In SQL Server 2008, the location of the Resource database is <drive>:\Program Files\Microsoft SQL Server\MSSQL10.<instance_name>\MSSQL\Binn\. The database cannot be moved.

Examples

A. Moving the tempdb database

The following example moves the tempdb data and log files to a new location as part of a planned relocation.

Note

Because tempdb is re-created each time the instance of SQL Server is started, you do not have to physically move the data and log files. The files are created in the new location when the service is restarted in step 3. Until the service is restarted, tempdb continues to use the data and log files in existing location.

1. Determine the logical file names of the tempdb database and their current location on the disk.

   SELECT name, physical_name AS CurrentLocation
   FROM sys.master_files
   WHERE database_id = DB_ID(N'tempdb');
   GO
   

2. Change the location of each file by using ALTER DATABASE.

   USE master;
   GO
   ALTER DATABASE tempdb 
   MODIFY FILE (NAME = tempdev, FILENAME = 'E:\SQLData\tempdb.mdf');
   GO
   ALTER DATABASE tempdb 
   MODIFY FILE (NAME = templog, FILENAME = 'F:\SQLLog\templog.ldf');
   GO
   

3. Stop and restart the instance of SQL Server.

4. Verify the file change.

   SELECT name, physical_name AS CurrentLocation, state_desc
   FROM sys.master_files
   WHERE database_id = DB_ID(N'tempdb');
   

5. Delete the tempdb.mdf and templog.ldf files from the original location.

See Also

Reference

ALTER DATABASE (Transact-SQL)

Concepts

Resource Database

tempdb Database

master Database

msdb Database

model Database

Moving User Databases

Stopping Services

Rebuilding System Databases

Other Resources

Moving Database Files

Starting and Restarting Services

Change History

Updated content
Updated the section "Moving the Resource Database" to indicate that the Resource database cannot be moved.